Forces between atoms and atomic planes in condensed metallic phases and in semiconducting silicon

Density functional theory for the pair potential in liquid Na near melting is first compared with that extracted by liquid structure inversion. All the main features are in quantitative agreement. Quantum chemical representations of metallic crystalline energies are then treated as a function of local coordination number and near-neighbor distance. K and Cu are especially referred to, in different lattice structures. Finally, the Tersoff potential based on density functional theory is discussed in relation to the cleavage force in ideal crystalline Si, and is related to bond breaking. © 1997 John Wiley & Sons, Inc. Int J Quant Chem 65: 907–917, 1997